On Mon, 5 Feb 2018, Devin Heitmueller wrote:
Hello Marton,
I thought you are working on an updated patch, or I just missed the new
one? The email you replied to here definitely contains the old, without
interleaved VANC autodetection or proper width for get_metadata.
I did some digging into this after discussion with Ray (both by
reviewing the SMPTE specs as well as doing some testing here with my
Sencore MRD4400 decoder). The use of VANC over both luma and chroma is
because it’s an SD format. Hence it will only be present in specific
modes. When doing HD formats, the VANC packets will be exclusively
found in the luma region.
Have you found which standard contains reference to interleaved VANC?
That said, the list of modes should probably be expanded to include all
the SD resolutions (although you’re unlikely to see CEA-708 over
non-NTSC streams). However I don’t think it would be a good idea to
attempt to ‘autodetect” by applying both algorithms over all VANC lines
regardless of mode.
I think the plan was to check if the mode is NTSC _and_ the first VANC
header is present in an interleaved way. So the HD modes would remain as
before.
I only found ITU-R BT.1364-3 which states that luma and chroma are
separate VANC spaces, so that is why I thought autodetection for even
NTSC would make it more compatible with newer equipment respecting this
recommendation.
If you think this is unnecesary then so be it, I have no experience with
real life baseband NTSC signals.
Regards,
Marton
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
